Muffler containing inner and outer end walls and longitudinal chambers



Oct. 30, 1951 J M 2,573,474

MUFFLER CONTAINING INNER AND OUTER END WALLS AND LONGITUDINAL CHAMBERS Filed April 28, 1949 19 13 F 1 20 i5 ,21 20 N 14 I I 135 F r -T 2 r 2 W 0H1. b 13 x- I I I Ii WI! 15 i .7 r V. 'I k 5 f M 7 Qvfl/ 55.2 17 1 H 23 w H v v'; 27 Inventor 127 Jo gph P77Zarx Patented Oct. 30, 1951 MUFFLER CONTAINING INNER. AND OUTER END WALLS AND LONGITUDINAL CHAM BEBS J osephP. Marx, Hartford, Wis. Application April 28, 1949, Serial No, 90,247

4 Claims.

The invention relates to improvements in mufflers and more particularly to an inexpensive mufller construction embodying novel structural characteristics especially adapting it for use in association with a V-type internal combustion engine.

Most known mufflers of the kind used to silence the exhaust gases of internal combustion engines, or the like, primarily are designed for use in association with in line types of internal combustion engines. A V-type internal combustion engine, however, has two exhaust manifolds, one on each side of the engine block. At present, it is common practice to connect one of the manifolds, as by a pipe, directly to a mufiier of conventional construction and to connect the other manifold for exhaust through the same muflier by connecting it, through a flexible pipe having a T connection, with the direct exhaust pipe. This results in the building up of highly objectionable excessive back pressure in the entire exhaust system. Other V-type engine installations involve the use of two separate and dis tinct mufliers, one for each exhaust manifold. Obviously, such dual installations are costly.

An early and, so far as applicant is aware, the only prior attempt to avoid these objectionable characteristics of installations referred to hereinabove has been the design of a single muffier of the kind shown in the expired W. R.

McCulla Patent No. 1,140,693, dated May 25, 1915. The McCulla Muflier embodies a highly objectionable structure because it fails to provide for straight line passage of exhaust gases there through. The exhaust gas inlets of the McCulla mufiier open into a large chamber from which the exhaust gases can pass only through a perforated inner wall into a second and smaller chamber. This second chamber exhausts its gases through perforations in a conduit which then conducts the gases to a tail pipe. Clearly, such a mufiier builds up terrific back pressures thus reducing engine efficiency. It undoubtedly is a muffler which would soon become unserviceable due to its burning or blowing out.

' The present invention is concerned with the provision of a single muiiier assembly having separate straight line passages for the exhaust gases from each manifold of a V-type internal combustion engine and it is, therefore, one of the objects of the invention to provide such a mufiler.

Another object is to provide a mufiier of a kind having two conduits extending therethrough for the unrestricted passage of exhaust gases and in which means is provided to cause the gases to be divided into a multiplicity of turbulent nondirectional streams of different volumes, lengths and velocities so as to absorb and destroy sound waves of all frequencies to provide maximum efficiency in silencing noise.

Another object is to provide a rugged muffler construction of the kind referred to which is easy and inexpensive to construct and may be installed quickly.

Another object is to provide a muflier having two distinct chambers surrounding two separate straight line exhaust gas passageways, and wherein each chamber may be divided into compartments so as to more effectively break up and destroy sound waves of all frequencies without establishing objectionable back pressures.

Other objects of the invention will appear from the following description and accompanying drawings and will be pointed out in the annexed claims.

In the accompanying drawings there has been disclosed a structure designed to carry out the various objects of the invention, but it is to be understood that the invention is not confined to the exact features shown as various changes may be made within the scope of the claims which follow.

In the drawings:

Fig. 1 is a longitudinal sectional view through a muffler embodying the features of the present invention.

Fig. 2 is a transverse sectional view taken substantially on line 2-2 of Fig. 1.

The mufiler illustrated in the drawing is of a type primarily designed for use in silencing the exhaust of internal combustion engines but, as

Will be understood as the description proceeds, the features of the invention may readily be embodied in other silencing devices especially designed for use in association with other sound creating mechanisms. The present muffler is, however, especially designed for use in association with a V-type internal combustion engine so as to afford practical and efficient means for silencing the noises of the exhaust gases with minimum back pressure.

As illustrated, the muffler consists of an outer tubular shell ll, preferably oval in section, suitably closed at each end by being provided with end headers including inner and outer end walls 12 and 13 respectively. The end walls l2 and I3 closing each end of the mufller are spaced apart to define a dead air space therebetween. The inner end wall I2 of each header has a pair of circular flanged openings l5. One opening in one ings IS in the opposed inner end walls 12. As

shown, the ends of the conduits iii are telescoped into the respective flanged openings iii of said end walls l2. Pipe fittings [9 having reduced diameters 28 are provided at each end of the muffler for purposes to be described presently. Each fitting l9 has its reduced diameter 20 telescoped into an end of a conduit l8 and its remaining portion projects through the space M between the inner and outer end walls and extends through an opening 21 in the outer end wall so as to project outwardly beyond the muliler ends. The fittings l9 are welded, as at 22, to the respective outer end Walls l3 and they are also welded, as at 23, to the respective flange surrounding the openings l5 in the inner end walls l2. The fittings l9 projecting beyond one end of the mufiier are each adapted to have connected therewith an exhaust pipe (not illustrated) leading from one side of the V-type combustion engine. The projecting ends of the fittings E9 on the other end of the muffler are each adapted to have connected thereto tail pipes (not shown) leading to the rear of the vehicle in which the mufiler is installed.

It should be quite evident from the description of the mufiier construction hereinabove recited that exhaust gases from each side of the V-type internal combustion engine flow freely in straight line conduits from the engine to the discharge ends of the tail pipes. The 'flow of exhaust gases is, therefore, unimpeded throughout its travel.

The muflier shell ll preferably is reinforced midway between its ends by a transverse wall 24 having a marginal flange, as at 25, so as to permit its being spot welded to the shell II. The wall 24 has fianged openings 26, each of which has one of the conduits I8 extending freely therethrough. It should be observed at this time that the flanged openings 26 preferably are of such diameter as to permit the conduits l8 to pass therethrough freely without any portion thereof resting in contact therewith. This affords an annular passage of small capacity surrounding each conduit 13 where it passes through the transverse wall 24 for purposes to be explained presently.

Silencing is obtained in the mufller by providing each conduit i8 with a plurality of perforations 21 preferably having external louvers 28 which permit a portion of the gases and sound waves passing through the conduits to escape and flow into the space between the conduits and the shell. It is desired that gases and sound Waves escaping through the louvered perforations 21 into the surrounding space be returned to the conduit from which they have flowed. To this end, the muffler is provided with a longitudinal partition 29 which lies between the conduits l8 and extends between the opposed inner end walls l2. It is suitably welded to said end walls and to the transverse wall 2 3 aswell as to the shell I l. The longitudinal partition thereby divides the interior of the muffler into a pair of cham-= 4 bers entirely separated one from the other and through each of which one of the conduits l8 extends. The transverse wall 24 divides each chamber into two compartments which may be in communication with each other through the annular space defined by th flanged openings 26 therein. This structure insures that escaping gases return to the conduit from which they have escaped through the perforations 21 therein and comingle with the main stream of gases passing through the conduit.

Maximum silencing efiiciency, with the least resistance to the flow of gases, is obtained by arranging the louvered perforations 21 in opposed pairs, as best illustrated in Fig. 2, so that the streams of gases flowing outwardly through each pair of perforations are directed toward each other by the opposed louvers 28 so a to create a turbulent mass, as distinguished from parallel streams. This comingling of the gas streams effectively breaks up the otherwise uniform sound waves therein contained and further prevents streams of hot gases from flowing into direct contact with the shell H and longitudinal partition 29. Accordingly, there is no localization of heat or premature burning out of the shell. Obviously, the return flow of gases from the space between the conduits and the shell and partition also is effectively disturbed by the divergence of the streams entering the main streams of gas flowing through the conduits. Because of the turbulence imparted to the gases entering the space surrounding each conduit, sound waves entering the perforations with the flow of gases returning to the conduits will be out of phase with each other and, because of this and the variance in their velocities, said wave will be out of phase with the sound waves in the stream flowing straight through the conduits. Consequently, all disturbing noises are effectivel elimi nated without building up objectionable back pressures in the exhaust system.

It is to be observed that gases and sound waves entering either of the compartments defined in the chamber by the transverse wall 24 may flow in restricted quantities from one chamber to the other longitudinally of the muliler. If desired, the annular spaces 25, provided where the conduits pass through the transverse wall, may be eliminated by providing suitable means to effectively close the same. This may be accomplished in the present muffler construction without impairing the effectiveness thereof. Other variations in the structural details of the muflier construction disclosed in the accompanying drawing and described hereinabove may be utilized without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. A muiiler of the type described comprising a tubular shell, an outer end wall at each end of said shell, an inner end wall spaced from each outer end wall, a longitudinal partition extending between the inner end walls dividing the shell into two longitudinal chambers, internal conduits coextensive with and one within each chamber, a pair of inlet and a pair of outlet fittings for exhaust gases extending through the inner and outer end walls, one of each pair being connected to one of the conduits to provide two straight line passageways for exhaust gases, said conduits being perforated to allow passage of gases and sound waves into and out of the respective chambers.

2. A mufiler like that described in claim 1 in which the chambers are divided into compartments.

3. A muffler like that described in claim 1 in which the perforations in the conduits are louvered.

4. A muflier of the type described comprising a tubular shell, a header in each end of said shell, said headers each consisting of inner and outer end walls, a longitudinal partition extending between the inner end walls dividing the interior of the mufiier into two chambers, a conduit in and coextensive with each chamber, each conduit having louvered perforations substantially throughout its length, the conduit ends being telescoped in openings in the inner end walls, said openings being of a size to cause the louvered openings in the telescoped ends of the conduit to be closed, and fittings extending through the outer end walls each having their inner ends telescoped into the respective ends of the conduits so as to provide straight line exhaust gas passages.

JOSEPH P. MARX.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

